RED BOX- Box that mimics the sound of a quarter being
entered into a payphone, fooling ACTS; possibly the secondbox (after the blue
box) to be created by phreaks.
Tone is created by a 6.5536 Mhz crystal, in the pure forms; there are a number
of soft boxes, tones in software for a computer. [Name comes from the box in
pay phones
that actually is red.]

If you've ever made a call from a pay phone and put in
real quarters, sometimes you may have heard a series of chirping noises in the
back- ground, really faint. Those are the tones that a pay phone hears when
you deposit money and there's a lot of ways that you can immitate these tones
to get free calls.

Before cellular (radio) telephones became cheap and widely
available, people who wanted to make telephone calls away from home typically
used payphones. Older model payphones signalled the deposit of coins by ringing
bells. A dime was represented by two dings, a nickel by one, and a quarter by
a lower-pitched chime. For local calls, the phone would activate when the price
of a local call (a nickel or a dime) was deposited. For long distance calls,
an operator would listen to the bell chimes as coins were deposited, would record
payment of the toll charge, and would then connect the call. With the advent
of solid-state technology, bells were replaced by electronic tones. One beep
was a nickel, two a dime, and five a quarter. This permitted completion of toll
calls without operator intervention,
because the tones could be detected by the automatic switching system at the
telephone company.

Phone phreaks came up with methods to play these tones
into the telephone's microphone, thus fooling the system into completing free
calls. These methods included playing back the tones using an audio recorder
(usually a tape recorder as magnetic tape was then the primary means of recording
audio).

A red box is a phreaking device that synthesizes these
tones, which are not unlike the DTMF tones used for dialing. Other devices which
generated these tones included modified Radio Shack tone dialers, and Hallmark
audio-recording greeting cards.

Red boxes no longer work in most western nations, the
pay phones either include filters on the handset to remove this sound, or in
many cases, use digital
systems that are not so easily fooled. The basic concept still works in many
other countries, however.